Compact air conditioning unit



Oct. 1950 N. A. PENNINGTON 2,527,569

COMPACT AIR comamcumc unrr Filed Sept 5, 1946 2 Sheets-Sheet 1 I 47 INVENTOR, 29 V y MEAL APE V/AGTO/V,

ATT RNEY Oct 31, 1950 N. A. PENNINGTON COMPACT AIR CONDITIONING UNIT I 2 Sheets-Sheet 2 Filed Sept. 5, 1946 I II III Ill mmwm mt m N 6 mm m A I m Patented Oct. 31, 1950 UNITED STATES PATENT OFFICE COMPACT AIR CONDITIONING UNIT Application September 5, 1946, Serial No. 694,972

16 Claims.

My invention relates to new and useful improvements in air-conditioning apparatus, and more particularly to the attaining of compactness in air-conditioning units.

In my copending applications, Serial No. 640,792, filed January 12, 1946, and Serial No. 676,962, filed June 15, 1946, which applications may be referred to for further details as to all common subject-matter, I show and describe several species of my basic invention, the object of which is to attain anhydrous evaporative cooling. The first of these two cited applications has matured into U. S. Patent No. 2,464,766, issued March 15, 1949. The objective is attained by evaporatively cooling (preferably by a circular absorbent pad, rotating partly in a trough of water and partly in the air-stream) one airstream (preferably a stream of exhaust air from the room), and then transferring the heat from an incoming air-stream by means of an anhydrous heat-exchange circular pad rotating partly in one air-stream and partly in the other.

It is the principal object of my present invention to devise a more compact model or models of the simplest species of the above-mentioned genus, although many of the ideas employed by me to that end could well find a place in the other species.

A further object of my present invention is to devise a portable model for single-room use.

A further object is to devise a heat-exchange pad of the same air-capacity as the disc-shaped pad of my two copending applications, yet with much reduced diameter.

A further object is to devise an air-conditioning machine which will cool less air a greater number of degrees, for use where my regular device would cause an excessive rate of change of air.

In addition to my principal objects, above stated, I have worked out a number of novel and useful details, which will be readily evident as the description progresses.

My invention consists in the novel parts and in the combination and arrangement thereof, which are defined in the appended claims, and of which two embodiments are exemplified in the accompanying drawings, which are hereinafter particularly described and explained.

Throughout the descr tion the same reference number is applied to the same member or to similar members.

Figure 1 is a vertical section of one variant of my present invention, namely the compact portable model.

Figure 2 is a portion of the same vertical section, modified so as to cool less air a greater number of degrees.

Figure 3 is a longitudinal vertical section of a third variant of my present invention, taken along the lines 33 of Figures 4, 5 and 6.

Figure 4 is a transverse vertical section, taken along the lines 4-4 of Figure 3.

Figure 5 is a transverse vertical section, taken along the lines 5--5 of Figure 3.

Figure 6 is a transverse vertical section, taken along the lines 6-6 of Figure 3.

Referring now to Figure 1, we see that H is the main container of the first variant to be described herein. I2 is an air inlet from outdoors. I 3 is an air outlet to outdoors. It is contemplated that the right-hand side of the figure will be placed against the outside wall of the room, with these two orifices projecting out through a window or other opening in the wall.

In inlet 12 there is a fan i 4, preferably a centrifugal fan, so disposed as to suck air in from outdoors, and impel this air into passage I.

In outlet I3 there is a similar fan l6, so disposed as to suck air from passage I1 and impel it out through outlet i 3.

I8 is a rotatable anhydrous heat-exchange pad of the same. general or specific sort as described and shown in my two copending applications. Copending application of Roger Sherman Hoar, Serial No. 677,295, filed June 1'7, 1946-, points out the desirability of building the'framework (i. e., the hub, spokes. and rim) of this pad out of plastic or some other non-heat-conducting material. However, there are certain advantages (including rigidity and durability) to the use of metal; and aluminum and magnesium (in spite of their high thermal conductivity) possess the advantages of lightness, cheapness, and mal leability. To reconcile all these considerations, I build the framework of my pad of aluminum or magnesium and then coat it with liquid plastic or other heat-insulating paint. This expedient falls within the genus of said Hoar invention, but is believed to be preferable to his species. This pad rotates in a casing l9, each face of which has two sectorial orifices, separated from each other by bridge 20. Left hand orifice 2| connects with passage l1. Right hand orifice 2|A connects with passage I5.- This casing, bridge, and orifices, are like elements 44, 43, 46 and 41, of copending Patent No. 2,464,766 where they are thoroughly described.

22 is a rotatable water-holding pad of the same general or specific sort as described and shown in my two copending applications. This pad rotates in a casing 23, each face of which has an opening 24 in passage I'l. Each of these openings is spanned by a bridge 25. The lower portion of pad 22 is submerged in water in trough 28. This casing, openings, bridge and trough are like elements 34, 38-31, unnumbered bridge, and 35, of copending Patent No. 2,464,766, where they are thoroughly described. The trough can be kept filled with water in any convenient manner, as shown and described in said application, or otherwise.

Louvres 21 lead from the room to passage ll. Louvres 28 lead from the room to passage l5.

Motor 29 drives the two fans It and H5 at a high rate of speed, through pulley 38, V-belt 3i, pulley 82 and common shaft 33, which latter is journaled on the main frame II at 34, 35, 38, and 31. This shaft, through worm 38 and worm-gear 3., drives shaft 40, which is journaled in bridges 28, and on the main frame at 4| and 42, and is drivingly keyed to heat-exchange pad I8.

Shaft 40 in turn, through bevel gear 43, and bevel gear 44, drives shaft 45, which is journaled in bridges 25, and On the main frame at 48, and which is drivingly keyed to water-holding pad 22.

The various gear-ratios are such that waterholding pad 22 rotates preferably at about 3 R. P. M., and heat-exchange pad l8 rotates preferably at about 30 R. P. M.

Feet 41 can be provided, if desired.

It is to be noted that rotating pads i8 and 22 are at a substantial angle (preferably a right angle) to each other. This enables me to combine free air-flow with a compact arrangement, and furthermore enables me to drive the shaft of one pad directly from the shaft of the other, which further simplifies my construction.

The operation of this variant is as follows. Exhaust air from the room enters the machine through louvres 21, and passes through waterholding pad 22, where it has its dry-bulb temperature adiabatically reduced to nearly its wetbulb temperature. The thus-cooled outgoing air then passes through heat-exchange pad I 8, which it cools to nearly the dry-bulb temperature of this air. This air is then sucked through fan l6, and passes outdoors through outlet 13.

The incoming air is sucked in through inlet l2, by fan I, and then passes through heat-exchange pad l8, which anhydrously reduces the dry-bulb temperature of this air to nearly that of the adiabatically cooled outgoing air. The incoming air then passes into the room through louvres 28.

It is to be noted that room inlet 28, through which cool air enters the room, is at a higher level than room outlet 21, through which warm air leaves the room. Inasmuch as relatively hot air tends to rise, and relatively cold air tends to fall, this arrangement minimizes cold floor-drafts, and assures a better mixing of the air in the room than would result from any other arrangement.

It is to be noted that outdoors outlet i3, through which indoor air leaves the machine, is at a lower level than outdoors inlet l2, through which the air to be cooled enters the machine. Inasmuch as relatively hot air tends to rise, and relatively cold air tends to fall, this arrangement assures that the highly humidified outgoing air (being slightly cooler than the outdoors air) will not be sucked back into the room. The elevation and upward direction of inlet l2 further guarantees against this.

Turning now to the variant of Figure 2, we see 4 that this second variant is identical to my first, except as hereinafter described.

In addition to the features of my first variant, described and shown in Figure 1 and hereinabove, my second variant has a feed-back passage 48, which takes from passage l5 one-third (or other predetermined portion) of the incoming air cooled by my machine, and feeds it back into the outgoing air stream in passage l1, before that air passes through water-holding pad 22.

This expedient performs to some extent, and in much simpler fashion, the same precooling of the outgoing air as is effected by more complex means, but to a greater extent, by the precooling device of the two variants of my copendin application Serial No. 676,962.

This expedient can be equally well employed in any of the other variants claimed in this application or in either of my two copending applications.

This expedient is useful whenever the room load is so heavy that an excessive rate of airchange is necessary in order to reduce the room temperature the desired number of degrees.

To get a clear mental picture of what this expedient accomplishes, let us compare it with the suitable heat-absorbing material.

more obvious alternative of merely increasing the capacity of our machine. It is true that merely increasing the face-area of the heat-exchange pad and the capacity of the fans by 50% would decrease the load by one-third. But this would be accomplished at the expense of increasing the rate of air-change in the room by 50%. Whereas, increasing the face-area of the heat-exchange pad by 50%, and feeding back this increase into the outgoing stream, a one-third reduction in load can be effected by less than a 50% increase in fan-capacity (inasmuch as in this expedient, the added air does not have to be forced out into the room, and then be dragged back into the machine), and with no increase the rate of airchange in the room. I

Turning now to Figures 3 to 6, let us consider my third variant.

5| is the main container. 52 is an air inlet from outdoors. 53 is an air outlet to outdoors, or the attic. 54 is the outlet from th room into the machine. 55 is the inlet to the room from the machine.

56 is a fan (preferably centrifugal) to suck outgoing air from space 51, and impel it outdoors through outlet 58.

58 is a similar fan to suck incoming air from space 59, and impel it into the room through inlet 55.

54 is an anhydrous heat-exchange pad, built on the same theory as those of variants l and 2 of this present application; and as those of my copending applications, but of radically different design, being in the form of a hollow cylinder. At each end is one of two hubs 60 and El. Radiating from each of these hubs, are spokes 82. Corresponding spokes are connected by radial partition 63 extending the length of the pad, but not extending inwardly more than about onethird of the distance from periphery to axis.

Between successive partitions 63 there is a peripheral packing 64 of metal-wool or other To help hold this packing in place and to add rigidity to the framework of the pad, diagonal bracing (not shown) or other appropriate means, may be employed.

The radial thickness of the packing of this var fi ll is determined by the same considera- -main frame by brackets 66 and 61.

tions as determine the axial thickness of the packing in my copending applications. The mean area of that portion of the inner and outer cylindrical surfaces of the packing of this variant lying between bridges, is the bottle neck of each air-stream.

The bridging of the pad of this variant, so as to prevent the by-passing of air from one airstream to the other, presents quite a problem, which I have solved in the following manner.

The two hubs 60 and BI are rotatably mounted on a non-rotatable shaft 85, firmly held to the This non-rotatable shaft supports an interior partition 68, which extends almost the length of the cylinder, and carries two curved interior bridges 69.

Exterior partitions project inwardly from the main container 5i, and carry two curved exterior bridges I l.

Each of the four bridges, just described, spans slightly more than one sector of the pad.

Exterior partition 12 blocks the upper half of one end of the cylinder, and exterior partition 12' blocks the lower half of the other end.

Accordingly it will be seen that two independent streams of air can pass through the pad, one through the upper half, and one through the lower half.

I3 is a rotatable water pad of the same general or specific sort as described and shown in my two copending applications, and in connection with the first variant described and shown in this present application. This pad rotates in a casing 14, each face of which has an opening 15, in passage 54. A part of each face of this casing 14 constitutes a bracket 16 or 11, for the support of shaft 18, which is drivingly keyed to pad I3. The lower portion of pad 13 is submerged in water in trough 19. This casing, openings, and trough, are like elements 34, 3631, and 35, of copending Patent No. 2,464,- 766, where they are thoroughly described. The trough can be kept filled with water in any convenient manner, as shown and described in said application, or otherwise.

Motor 80 drives the two fans 56 and 58 at a high rate of speed, through pulley 8|, V-belt 82, pulley 83, and common shaft 84, which later is journaled in the main frame at various unnumbered but obvious points.

Shaft 84 in turn, through sprocket 85, sprocketchain 86, and sprocket 81, drives hub SI of heatexchange pad 64, at about to R. P. M. The framework of pad 64 in turn drives hub 60.

Hub 80 then, through sprocket 88, sprocketchain 89, and sprocket 9U, drives shaft 18, and thereby water-holding pad I3, at about 2 or 3 R. P. M.

It is to be noted that my two air-streams pass through rotating pads 13 and 64, as through the two pads of my first hereindescribed variant, at right-angles to each other. This enables me to combine free air-flow with a compact arrangement.

The operation of this present variant is as follows. Exhaust air from the room enters the machine through passage 54, and passes through water-holding pad 13, where it has its dry-bulb temperature adiabatically reduced to nearly its wet-bulb temperature. The thus cooled outgoing air then enters the lower half of the hollow interior of heat-exchange pad 64, and passes radially outward through the lower half of the packing of this pad, into space 51, thereby cooling this pad to nearly the dry-bulb temperature of this air. This air is then sucked through fan 56, and passes outdoors through passage 53.

The incoming air is sucked into the machine from outdoors, through air-inlet 52. Thence it passes radially inwards through the packing of the upper half of heat-exchange pad 84, into the upper half of the hollow interior of that pad, which anhydrously reduces the dry-bulb temperature of this air to nearly that of the adiabtically cooled outgoing air. Thence the incoming air, passes out through the right-hand end of pad 64, thence through fan 58 and passage 55 into the room.

It is to be noted that outdoors outlet 53, through which indoor air leaves the machine, is at a lower level than outdoors inlet 52, through which the air to be cooled enters the machine. This arrangement is the same as in the first and second variants shown and described in this present application, and accomplishes the same advantages.

It is to be noted that in all three of the variants shown and described in this present application, as in all the variants of my copending applications, the two air-streams pass through the successive layers of packing of my anhydrous heat-exchange pads in the opposite direction from each other, thereby attaining the essential advantages of nearly ideal counterfiow, which I have thoroughly explained in my copending applications.

Having now described and illustrated three forms of my invention, I wish it to be understood that my invention is not to be limited to the specific forms or arrangements of parts herein described and shown.

Iclaim:

1. An air-conditioning unit, having: two airpassages; a water-tank; an air-permeable waterholding pad, rotatable partly in the tank and partly in one air-passage; an air-permeable nonhygroscopic heat-transfer pad; rotatable partly in each air-passage; means for rotating the two pads; means for impelling air in the first passage, first through the water-holding pad and then through the non-hygroscopic pad, whereby this stream of air is first cooled by evaporation and then cools the non-hygroscopic pad; and means for impelling air in the second passage through the non-hygroscopic pad, whereby this stream of air is anhydrously cooled by the non-hygroscopic pad, and then passes into the space to be conditioned; characterized by the fact that the direction of passage of air through the water-holding pad is substantially at a right-angle to the direction of passage of air through the heat-transfer pad.

2. An air-conditioning unit according to claim 1,,further characterized by the fact that the axes of the two pads are at approximately right angles to each other.

3. An air-conditioning unit according to claim 1, further characterized by the fact that the axis of the water-holding pad is substantially horizontal, and that the axis of the heat-exchange pad is substantially vertical.

4. An air-conditioning unit according to claim 1, further characterized by the fact that the heatexchange pad isa hollow cylinder through the walls of which the air passes radially.

5. A rotatable heat-transfer pad for an aireonditioning unit, in the form of a hollow cylinder, comprising: a hub and spokes at each end only of the cylinder; a series of substantially ass-moo radial partitions impermeable to air, adjacent the periphery of the cylinder only and extendin longitudinally thereof; and a packing of nonhygroscopic air-permeable highly heat-absorbent material between the partitions; each end of the cylinder being open from the hub to the peripheral packing.

6. In the heat-exchanger of an air-conditioning unit, the combination of a rotatable hollow cylindrical heat-transfer pad, comprising a hub and spokes at each end of the cylinder, series of substantially radial partitions impermeable to air, adjacent the periphery of the cylinder and extending longitudinally thereof, and a packing of non-hygroscopic air-permeable highly heatabsorbent material between the partitions; an air-passage leading toone side of the outer curved surface of the pad; 8. second and separate airpassage leading to the diametrically opposite side of theouter curved surface of the pad; a nonrotating partition separating these two passages, and extending the length of the pad, and also blanking the outer curved surface thereof for the length of the pad and for a width equal to slightly more than the distance between two partitions of the pad; a similar partition diametricall across the pad from the first; a third and fourth separate air-passage, each leading to slightly less than half of an open end of the pad, each such half corresponding to one of the two mentioned sides of the outer curved surface of the pad; partitions blanking the open ends of the pad except where the third and fourth passages lead; a nonrotating partition within the hollow cylindrical interior of the pad, extending the length of the pad and extending diametrically across the hollow cylindrical interior of the pad, and having means at each diametrically opposite extremity of the partition blanking the curved inner surface of the pad opposite to, and to substantially the same extent as, the two first-mentioned blanking means; all the partitions and blanking means being such as to prevent appreciable air-leakage through the pad from one side passage and one end passage to the other pair of such passages.

7. A heat-exchange according to claim 6, characterized by the fact that the heat-transfer pad is mounted for rotation with respect to a fixed longitudinal shaft which rigidly supports the nonrotating partition within the pad and the means blanking the inner surface of the pad.

8. An air-conditioning unit according to claim 1, further characterized by the fact that there is a by-pass passage for feeding back a portion of the air cooled by the heat-exchange pad direct from the second passage into the first passage to mingle with the air therein prior to said air passing through the water-holding pad.

9. In an air-conditioning unit, the combination of: two air-passages; a water-tank; an airpermeable water-holding pad, rotatable partly in the tank and partly in one air-passage; an airpermeable non-hygroscopic heat-transfer pad, rotatable partly in each air-passage; means for rotating the two pads; means for impelling air in the first passage, first through the water-holding pad and then through the non-hygroscopic pad, whereby this stream of air is first cooled by evaporation and then cools the non-hygroscopic pad; means for impelling air in the second passage through the non-hygroscopic pad, whereby this stream of air is anhydrously cooled by the non-hygroscopic pad, and then passes into the space to be conditioned; and a. by-pass passage for feeding back a portion of the air cooled by the heat-exchange pad direct from the second passage into the first passage to mingle with the air therein prior to said air passing through the water-holding pad.

10. An air-conditioning unit according to claim 1, further characterized by the fact that the axles of the two pads are directly geared together.

11. An air-conditioning unit according to claim 1, further characterized by the fact that the entrance to the first passage is appreciably below the exit from the second passage.

12. An air-conditioning unit according to claim 1, further characterized by the fact that the entrance to the second passage is appreciably above the exit from the first passage.

13. An air-conditioning unit according to claim 1, further characterized by the fact that the entrance to the first passage is appreciably below the exit from the second passage; and that the entrance to the second passage is appreciably above the exit from the first passage.

14. In an air-conditioning unit, the combination of two air-passages; a water-tank; an airpermeable water-holding pad, rotatable partly in the tank and partly in one air-passage; an air-permeable non-hygroscopic heat-transfer pad, rotatable partly in each air-passage; means for rotating the two pads; means for impelling air in the first passage, first through the waterholding pad and then through the non-hygroscopic pad, whereby this stream of air is first cooled by evaporation and then cools the nonhygroscopic pad; and means for impelling air in the second passage through the non-hygroscopic pad, whereby this stream of air is anhydrously cooled by the non-hygroscopic pad, and then passes into the space to be conditioned; characterized by the fact that the entrance to the first passage is appreciably below the exit from the second passage.

15. An air-conditioning unit according to claim 14, further characterized by the fact that the entrance to the second passage is appreciably above the exit from the first passage.

16. An air-conditioning unit according to claim 1, characterized by the fact that the heattransfer pad includes substantially radial partitions, the space between the partitions being filled with non-hygroscopic air-permeable highly heat absorbent material, and the partitions being coated with poorly-heat-conducting material.

NEAL A. PENNINGTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,762,320 Wood June 10, 1930 2,464,766 Pennington Mar. 15, 1949 FOREIGN PATENTS Number Country Date 387,517 Great Britain Feb. 9, 1933 548,400 France Oct. 20, 1922 

